1. You can e-mail sites:

    https://991.com/Buy/ProductInformation.aspx?StockNumber=114422&PrinterFriendly=1

    https://eil.com/fulltext/search.asp?SearchText=u2+pop+fridge+magnets&cboProductType=15&cmdGo.x=13&cmdGo.y=14&Sortby=title

    And ask them if they'd know. Since they buy and re-sell though, they may offer you a low end price. Whatever they tell you, I'd add 20-30% and consider that fair market value...
  2. a set of these went for £52 on ebay, if that helps.
  3. They were avaible for sale on shows stands
  4. How did you find it? I did an "advanced search" and nothing came up, just the cheap Chinese-made ones that go for $4